This invention relates to a device, a program automaton for weaving machines, finding application in the textile industry, especially in weaving and knitting.
A program automaton for weaving machines is known (which is described in Bulgarian Authorship Certificate No. 14496 and corresponding U.S. Pat. No. 3,674,991) with program nodes where a block for programming the weft comprises three or more series-connected electronic counters with decimal decoders, one electronic counter with decoder or two decade counters with decoders, playing the role of electronic switches, and a number of four-input AND-gates which number depends upon the number of the outputs of the decoder of the electronic switch. It is known as well that with ten-positional keys, connected with the outputs of the decoders and the inputs of the AND-gates, the program can be set. It is well known that all electronic counters applied in the program automaton are bidirectional in order to return back or reverse the program, which is necessary in view of the technological requirements of weaving, i.e. the necessity of deweaving several wefts, in the event that the stopping mechanism is not in action, to avoid faults in weaving.
Modern electronic counter circuits are bidirectional with two inputs--one for adding and another for subtracting. Therefore, they can add from 0 to 9, if decimal, and from 0 to 15, if hexadecimal. Conversely, they can subtract from 9 to 0, or from 15 to 0, repeating the cycle for addition and for subtraction. The counters operate similarly also when they are series-connected, i.e. for counting units, tens, hundreds, etc. The known program automaton for weaving machines is realized in a way that, with a minimum number of counters and minimum time for programming, it is possible for a large range of repeats to be set, e.g. to set a program of 1600 wefts with three counters for only two minutes, with 16 color tapes or bands in the repeat. Only two counters--for units and tens--are used for that purpose, along with one counter-switch, as at every one of the 16 colors after counting out one of them, the two counters are nulled and rebegin the counting. At a given decision of the program automaton, the weaving (adding) does not create problems. The deweaving (subtraction), when a deweaving is only of wefts from the color to which position the counter-switch is set, also does not create problems. However, a disadvantage of the known automaton is that when the deweaving has to continue to another color of the repeat, there are some difficulties at the returning of the counter-switch and at the series-connected counters, especially for the subtraction of digits, e.g. 100-16, 100-24, 100-36, 100-17, etc., because the counters for subtraction only count from 99 to 0, etc.